#include        <stdio.h>

#include        <stdlib.h>

#include        <unistd.h>

#include        <fcntl.h
>

#define BUFFERSIZE      4096

#define COPYMODE        0644


void oops(char *, char *);


int main(int argc, char *argv[])

{
	
int in_fd, out_fd, n_chars;
	
char buf[BUFFERSIZE];
	
if (argc != 3) 
{
		
fprintf(stderr, "usage: %s source destination\n", *argv);
		
exit(1);
	
}

	
if ((in_fd = open(argv[1], O_RDONLY)) == -1)
		
oops("Cannot open ", argv[1]);

	
if ((out_fd = creat(argv[2], COPYMODE)) == -1)
		
oops("Cannot creat", argv[2]);

	
while ((n_chars = read(in_fd, buf, BUFFERSIZE)) > 0)
		
if (write(out_fd, buf, n_chars) != n_chars)
			
oops("Write error to ", argv[2]);
	
if (n_chars == -1)
		
oops("Read error from ", argv[1]);


	
if (close(in_fd) == -1 || close(out_fd) == -1)
		
oops("Error closing files", "");

}


void oops(char *s1, char *s2)

{
	
fprintf(stderr, "Error: %s ", s1);

	perror(s2);
	
exit(1);

}
